A. Field of the Invention
This invention relates to an overhead stowage bin mechanism, and more particularly to its self-aligning bearing with improved installation and repair features.
B. Background of the Invention
The present invention is an improved mechanism to the basic mechanism disclosed in U.S. Application Ser. No. 973,424, now U.S. Pat. No. 4,275,942.
The present overhead stowage bin mechanism is particularly adapted for use in passenger airplanes. Each end of the bin is supported by a pair of pivoted arms of unequal length so proportioned that the bin moves from its stowed position downward and slightly forward, at the same time tilting slightly for ease of access. The arms interengage in the down position to increase rigidity. A spring cartridge is connected to each of the upper arms to counterbalance the weight of the bin, and also is arranged to hold the bin in the down position. The upper arms are interconnected by a torque tube, and a snubbing device is also included in the mechanism. However, the most important parts of the mechanism are the self-aligning bearings which are employed between the bin walls and the arms. The mechanism, according to Federal Aviation Administration specifications, must support a 300 pound weight hanging free on the stowage bin without signs of misalignment. Installation or removal of a bin is very cumbersome since a bin is generally mounted in a row of 50 or 60 bins.
In the prior art the bins were mounted to the arms outside of the bin since the inside had to remain flush for luggage. Thus, removal of one bin meant disconnection of the bin next to it in order to gain access for removing arms, bearings, etc. Furthermore, such removal required the presence of two to three repairmen.
Accordingly, the present invention has a specific bearing design which requires only one repairman for bin installation, dismantling, or repair.
The bearing design incorporates three main parts:
(a) a bearing axle retainer, mounted in the arm;
(b) an internal bin self-aligning needle housing with automatic axle retention means; and
(c) an external bin flat nut which holds the housing as one unit onto the bin wall.
The only patent of interest which was observed in the art was U.S. Pat. No. 3,512,328 which discloses a male and a female boss assembly associated with a fastener and wherein the bosses are threadably interconnected so as to clamp an associated structure as proposed.
The referenced patent shows some identical features with the bearing axle retainer of the present invention, but fails to disclose the axle retention means, the mounting of the self-aligning needle housing and other specific features designed for the bin mechanism.
Accordingly, the present invention provides for the following advantages and improvements over the prior art:
1. The stowage bin can be replaced by one man, thus allowing a great savings in maintenance and installation costs.
2. The stowage bin has self-aligning needle bearings which are so designed as to prevent rocking of the bin; thus, perfect linear control is obtained when the bin is moved from stowage to loading position.
3. The bin material, as well as the clamping boss material, does not require a flush surface as required in the prior art to enhance alignment.
4. The bearing unit can be installed on bin materials of different thicknesses without losing any of its properties and advantages.
5. The bin can be removed or installed without disturbing adjacent bins.
6. The internal bin bearing mountings have no hard edges for luggage to be caught on.